Fiberglass, 1.5 Oz Mat, Pre-cut & Packaged, 50" Wide, 5 Yd Long Fiberglass Mat is the most basic and commonly used reinforcement in composites Used as a skin coat to bond Gelcoats Used between rovings and cloths as a binder and to bond substrates and cores in a laminate Generally Mats are made with chopped roving strands and bonded with a resin-based binder 1-1/2 Oz Mat is approximately 1/16" thick laminated